Jennifer Aniston poses at the premiere of "The Switch" at the Arclight theatre in Hollywood, Calif. (Photo : Reuters)

Rumors persist that Jennifer Aniston is pregnant, but now she allegedly is having twins.

In the latest issue of the tabloid OK! Magazine Aniston is featured with the headline, "Getting Ready for Twins," and shows Aniston with her 41-year-old fiancé Justin Theroux.

The cover also stated that plans were already underway for the birth as well as a nursery and details on potential godparents, according to CelebDirtyLaundry.

More gossip flared from a December cover issue of OK! that ran a story about the 43-year-old's supposed pregnancy.

The headline for the tabloid stated: "Jen: Yes, I'm pregnant - with twins! The joyful moment she found out. A boy and a girl - and their unusual names! Excited Jen tells friends - 'I'm so thrilled!'"

A source for the magazine claimed Aniston recently underwent "extensive fertility treatments" and that she finally "hit the jackpot - big time."

"She was beyond excited the moment she found out, [telling friends] 'I'm so thrilled'...The fertility treatments weren't easy on her - but it looks like they paid off," the alleged source added.

The source also claimed that Aniston is going to keep the baby a secret until llater in the pregnancy.

"She's going to keep this as hush-hush as possible until she's at least four or five months along," said the source.

The magazine prompted rumors last year about the "Friends" actress's alleged pregnancy.

Aniston graced the September issue of OK! with the headline, "Finally It's Baby Time!"

Aniston and Theroux spent the Christmas holiday at a resort in Cabo San Lucas, Mexico. Many pregnancy rumors ceased when she was spotted relaxing in the sun with her toned body and flat abs in a pink bikini top while lounging poolside at the hotel cabana with no baby bump.

Theroux popped the question to Aniston in 2012 and they are expected to tie the knot later this year.